Patent GB-767207-A (GB)
Title: Improvements in or relating to sorting apparatus
IPC: B07C5/08
Filed: 1954-01-07
Abstract: 767,207. Sorting by gauging surface roughness. BICKLEY, E. H. Jan. 7, 1954 [June 15, 1953], No. 461/54. Class 106 (2). In an apparatus for sorting ball bearings according to surface imperfections means are provided for presenting the entire surface of each ball to a scanning device and for discharging each ball into one of two compartments according to its grading. A plunger 4, Fig. 2, operated by an arm 5, a spring 8 and a cam 7, is shown discharging a scanned ball 9 through a tube 10 to a sorting device 31, and replacing the scanned ball by an unscanned ball. The plunger is magnetized so that the unscanned ball remains at its end until pushed upwards by a piston 12, controlled by a spring 13 and a cam 15, to the scanning mechanism where the ball is rotated by four rubber rollers 16, 17, Fig. 1, driven by a motor 18, the rollers 17 rotating the ball rapidly about an axis parallel to their driving shaft 19, and the rollers 16 rotating the ball slowly about an axis parallel to their driving axis 22, driven by a worm gearing from shaft 19. The piston 12 is of square cross-section and is surmounted by a cage construction consisting of four wire guides 14 which loosely hold the ball and ensure that when the piston is lowered the ball also is drawn down. The entire surface of the ball is thus presented to a scanning brush 24 attached to a piezo crystal 25 which, when the brush is deflected by a pit hole or roughness on the surface of the ball, generates sufficient voltage to trigger a thyratron. The electrical circuit, Fig. 4, includes two switches 311 and 32 the former of which is opened after each ball is discharged in order to extinguish the thyratron if it has fired, and the latter of which is usually closed, thus shorting the crystal except at that part of the cycle of operation of the apparatus when a ball should be being scanned between the scanning rollers. This latter switch is necessary to prevent the thyratron firing as a ball is pushed against the brush immediately prior to scanning. In operation when a ball with a surface defect is scanned the valve will fire and energize a magnet 30 to operate a deflecting plate 31, so that as the ball is discharged it is directed into the appropriate compartment of a container 11. In a second embodiment, Fig. 7, the ball is rotated by a pair of rollers 37 about an axis parallel to their driving shaft 47 and is moved by two friction pads 50, 51 fixed on rods 56, 65 slidably mounted in pivoted bearings 57, 67, the pads being driven by cranks 52, 61, which are driven from shaft 47. In a third embodiment, Figs. 12, 13, the means for presenting the entire surface of each ball to the scanning brush comprises two rubber driving rollers 84, 85 fixed to two slidably mounted shafts 86, 91, two strip springs 101, 102 pressing against the shafts, flexible rubber rollers 87, 92 for transmitting the rotary motion of the main driving shaft 88 to the shafts 86, 91, and a plate 100 resting loosely on the main shaft, the plate being urged against a member 94 which also rests loosely on the main shaft but which rotates with the shaft because of a pivotal connection 95. Also rotating with the main shaft and with the member 94 is a collar 98 which, by means of two set screws 96, 97, maintains the rotating member 94 at a certain inclination to the shaft. In operation the member 94 rocks the plate 100 and causes the rotating shafts 86, 91 to slide laterally in their bearings against the pressure of the springs. The plate 100 is prevented from rotating with the main shaft by an extension 103 which moves in a hole 104 in the base of the support. The third embodiment is intended for use with a modified form of the apparatus, Fig. 10, in which the piston and its cage are replaced by a spring-pressed anvil 81 and a fixed ring 80, the ball being forced between the anvil and ring by the loading plunger 72, and the scanning brush extending through the ring.